Conventional automatic vehicle driving technologies include semi-automatic driving, such as following travel control that performs automatic acceleration and deceleration control to keep a target distance from a preceding vehicle detected by a radar or other sensors. Also proposed in recent years is semi-automatic driving, such as automatic steering control that maintains a current lane with reference to a white line detected by a camera or other sensors, and full-automatic driving that autonomously controls all of acceleration, steering, and braking by using multiple sensors provided on a subject vehicle.
In case of automatic driving that uses a sensor, however, a stop of automatic driving may be necessary when the sensor is in an abnormal condition.
For meeting this necessity, there has been disclosed in Patent Literature 1, for example, a technology that stops automatic driving when detection accuracy of a sensor used for automatic driving decreases. According to the technology disclosed in Patent Literature 1, it is determined that an output from a subject vehicle position detection means is abnormal when a shift amount of a subject vehicle calculated based on a subject vehicle position sequentially detected by the subject vehicle position detection means with a global positioning system (GPS) is extremely larger than a shift amount of the vehicle calculated based on a vehicle speed sequentially detected by a vehicle speed detection means. When it is determined that the output from the subject vehicle position detection means is abnormal, a part or the whole of functions of a traveling control device stops.